And the findings are brutal for Snapchat and Skype: Amnesty says they’re just not doing enough.

“Privacy is a human right. It is a fundamental part of human rights,” said Sherif Elsayed-Ali, Head of Amnesty International’s Technology and Human Rights Team.

“So when people are sending messages to their friends, to their loved ones, to their family, they want this to be private. They don’t want companies to be able to see that. They don’t want governments, who are trying to spy on people, to be able to see that either.”

Strong encryption is key

Youngsters who constantly share personal details and photos over Snapchat are especially at risk of having their data intercepted, says Amnesty.

Skype, Blackberry Messenger and China’s Tencent were also among the worst ranked because they don’t use end-to-end encryption – a way of scrambling data so that only the sender and recipient can see it.

A spokeswoman for Microsoft said the company disputed the analysis, contending that Skype does offer end-to-end encryption.

“We agree with Amnesty International about the importance of encryption. At the same time, this report does not accurately reflect Skype’s comprehensive work to protect people’s privacy and security,” a statement from the tech giant read.

The most private

While no company guaranteed absolute privacy, Facebook Messenger and WhatsApp got high marks for using end-to-end encryption. Amnesty says this should be part of the default privacy protections all messaging services must feature. That would ensure more privacy for millions of users, and also better protect journalists and activists from spying and cyber-crime.

Amnesty is also calling on tech companies to publish all the details of their policies and practices to protect users’ privacy and freedom of expression.

“If we do not build very strong systems of protection now, including through very strong encryption, then we will wake up twenty years from now and find that there is no such thing as privacy anymore,” said Amnesty’s Elsayed-Ali.